Heat-producing composition



Patented July 23, 1940 UNITED STATES PATENT OFFICE The Kendall Compan tion of Massachusetts y, Chicago, 111., a corpora- No Drawing. Application May 9, 1936,

Serial No. 78,938

10 Claims.

This invention relates to chemical heating compositions of the type which produce heat by chemical action with water.

One of the objects of the invention is to pro- 5 vide a heating composition which will react chem ically with water to produce a substantial amount of heat, thereby adapting the composition to a wide variety of uses, for example heat pads, the permanent waving of hair, etc.

Another object of the invention is to provide a composition of the type specified, in which one or more of the ingredients, upon addition of water, produces a solution which is alkaline in reaction and attacks a base metal with the evolution of 5 heat.

A further object of the invention is to provide a chemical heating composition which when used in the permanent waving of hair will react in a suitable ionizing medium, such as water, to provide a solution which is capable of swelling the hair, thereby rendering the mixture useful both as a source of heat and as a means for conditioning the hair concurrently with the formation of a wave therein.

Other objects and advantages of the invention will be apparent from the following detailed description, wherein I have set forth the types of ingredients which are combined to form the improved composition.

Although the combination hereinafter described .has a wide variety of applications, it is particular- -ly well adapted for use in the permanent waving of hair and in describing it I shall, therefore, refer particularly to the features which render it 35 especially desirable for this use.

At the present time it is the practice, in forming a permanent wave in hair, first to apply a waving solution which swells and softens the hair, thereby rendering the hair more susceptible to de- 40 formation, which is an essential step in the waving process. Generally the waving solutions are alkaline in reaction, a common solution compriscarbonate, and sodium tetraborate. Thus after 45 around a forming bar, a pad saturated with the Where chemical heat mixtures are used to provide 5 composition in an aluminum foil container. This container is perforated on one surface to allow the introduction of water to the mixture. This latter step is generally accomplished by moistening an absorbent pad which may be permanently fastenedto the heating'unit. A layer of'moising a mixture of ammonium hydroxide, sodium a curl has been fashioned by wrapping the hairalkaline solution is wrapped around the curl.

the heat, a common practice is to enclose the ture-proof paper is also usually provided in these units for the purpose of covering the moistening pad and preventing any migration of chemicals from the perforated foil container, through the absorbent cloth to the hair.

Up to the present time, chemical heating mixtures used in permanent waving have been acid in nature and usually consisted of a metal, such as aluminum, in combination with one or more electrolytes at least one of which was acid in reaction. An acid condition seemed to be essential for a satisfactory evolution of heat. It will be apparent that in using a mixture-of this type in a pad which is wrapped around hair which has previously been saturated with an alkaline waving solution, it is desirable that the pad be carefully separated from the hair, as otherwise the alkaline swelling solution might become mixed with the acid solution of the heat mixture, with the result that both solutions would become. more or less neutralized and both the action of heating and the action of swelling would thus be seriously impaired.

The heat-producing combination forming the subject matter of the present invention depends for its source of heat upon the action of ingredients which are alkaline in character and are thus unaffected by the alkaline waving solution. Also by using heating ingredients which are alkaline in character, I may eliminate the separate steps involving application of an alkaline waving solution to the hair. which contains an alkaline composition, the moistening pad which is used to start the generation of heat may be placed in direct contact with the hair, thus allowing the soluble alkaline ingredients to seep from the pad into the hair to effect a swelling thereof. I am thus able in one operation to accomplish the steps of both swelling and heating the hair.

The effectiveness of the swelling in the example just discussed may be greatly enhanced by the simple expedient of moistening the pad which starts the generation of heat, with a normal swelling solution instead of water. An equivalent procedure would be to impregnate the absorbent pad with the desired alkaline electrolytes. The application of water would then immediately produce a suitable swelling solution. In any event, my composition allows a very material simplification of the technique now employed in the permanent waving of hair with chemical heating mixtures.

In its simplest form the composition which I havedeveloped comprisesa mixture of a metal 5 By adopting a heating unit metals, may be used in the mixture.

and a substance which, upon addition of water, will dissolve or hydrolyze to form an alkaline solution which will attack the metal with a resultant evolution of heat. Practically any metal which is oxidizable in an alkaline solution, other than the alkali and alkaline earth metals and the noble Aluminum is the preferred metal although other metals such as magnesium, manganese, zinc, iron, and the like may also be used. While iron is not suitable for use in products having high heat requirements such as a pad for permanent waving of hair, it.

will produce practical compositions for use in other fields where the heat requirements are not so severe.

With regard to the alkaline electrolyte which may be used in combination with a metal such as aluminum, barium hydroxide is one example of a staisfactory compound. A mixture consisting of five grams. of aluminum and ten gram'sof barium hydroxide will, when treated with water, generate a very substantial amount of heat in a comparatively short period of time. The rate of heating, as well as the duration of the heat and the peak temperature obtained, may be excellently controlled by regulating the proportion of the ingredients and through the addition of regulated amounts of inert fillers such as talc, fullers earth, wood flour and the like.

Upon the additionof water to the mixture just described, the barium hydroxide is believed to attack the aluminum to form barium aluminate. This action is highly exothermic. However, the rate of this reaction may be considerably increased through the addition of an electrolyte which will react to generate a second alkaline substance which reacts readily with the base metal. Among examples of such electrolytes may be mentioned the sulphates, carbonates, chromates and fluorides of the alkali metals. of this type would comprise the following:

Grams Aluminum 5 Barium hydroxide Sodium sulphate 2 The action of the mixtures just described is very vigorous and the following equations show the probable reactions upon the addition of water:

Since the above compositions are alkaline in reaction, their reactivity is unaffected by alkaline hair-waving solutions. Moreover, as previously described, I am able to apply such compositions in a perforated pad, directly to the hair which has been wound on the forming bar, without preliminarily treating the hair with a waving solution. The alkaline ingredients in the heating composition and in the moistening cloth will efiect swelling of the hair at the same time that the heating action is taking place.

In the two foregoing examples, I may use in lieu of barium hydroxide or barium hydroxide in combination with sodium sulphate, other nondeliquescent alkaline electrolytes such as lithium hydroxide and the soluble carbonates, borates and acetates of the alkali and alkaline earth metals. Electrolytes of this class hydrolyze when dissolved in water to provide an alkaline solution which will attack the metal and liberate heat.

While deliquescent alkaline electrolytes such as sodium hydroxide are effective in generating heat, their deliquescent nature introduces dim- A typical mixtureculties in handling the composition, since moisture must be carefully excluded, prior to moistening to initiate the generation of heat. Furthermore, the heat-producing action of alkalis of this I nature is so vigorous that, if they are to be used in contact with the human body, as in hair waving, the violence of the reaction must be tempered by careful control of proportions of the ingredients and/or by the use of inert fillers.

The use of an ammonium salt in the mixtures previously described is very desirable, particularly where the mixtures are to be used in the hairwaving art. For example, the addition of a few grams of ammonium sulphate to the above-described barium hydroxide mixture, will result in evolution of ammonia fumes when water is added. This vapor penetrates into the curl and serves as an effective swelling agent for the hair. Other ammonium salts such as the oxalate, phosphate and carbonate would function in a similar manner. I

It is also desirable when these mixtures are to be used in such a way that air is partially or wholly excluded from the mixture, to add a source of oxygen to the composition. Examples of suitable oxidizing agents which have been found to function very efiectively are the chlorates, perborates, permanganates and dichromates of the alkali and alkaline earth metals. The quantity of these materials to be added will depend entirely upon the heat effects desired. When more than fifty percent of such compounds is added, mixtures having very high reaction rates are produced. Such reactivities are extremely'desir-able in many fields.

With regard to the form that the base metal may take in the foregoing compositions, it should be understood that this may be varied to suit the requirements of a given use. Metals in the form of powders, turnings, wire and foil may be used to advantage where their particular physical forms lend themselves to given products.

The physical form of the heating units may also be greatly varied without departing from the spirit of my invention. These forms may, for example, be intimate mixtures of the various materials in powdered form, or laminated structures in which the reacting ingredients are distributed throughout one or more layers.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom but the appended claims should be construed as broadly as permissible in view of the prior art.

What I regard as new and desire to secure by Letters Patent is:

1. A chemical heating combination adapted for use in. treating hair to form a permanent Wave therein, comprising a reactive metal selected from the metals positioned below the alkali and alkaline earth metals in the electromotive series of metals, and a non-deliquescent hydroxide which in the mixture is stable within practical limits under normal conditions of storage and of handling in the process of waving hair involving considerable exposure in open air, and which upon addition of a suitable ionizing medium will produce an alkaline solution which will attack the said reactive metal with the evolution of heat.

2. A chemical heating combination comprising a reactive metal selected from the group consisting of magnesium, aluminum, manganese, and zinc, and an electrolyte comprising a relatively stable, non-deliquescent hydroxide of an alkaline ii. i v

earth metal, which electrolyte, upon addition of a suitable ionizing medium, will produce an alkaline solution which will attack said reactive metal with the evolution of heat.

3. A chemical heating combination comprising a reactive metal selected from the metals positioned below the .alkali and alkaline earth metals in the electromotive series of metals, and an electrolyte comprising a relatively stable, nondeliquescent alkaline hydroxide selected from a group co isting of barium hydroxide, lithium hydroxide and hydroxides having like properties, such hydroxides being of greater stability than sodium or. potassium hydroxide, said electrolyte, upon addition of a suitable-ionizing medium, being adapted to produce an alkaline solution which will attack said reactive metal with the evolution of heat.

4. A chemical heating composition comprising a reactive metal selected from the group consisting of magnesium, aluminum, manganese, and zinc, and an alkaline electrolyte comprising barium hydroxide.

5. A chemical heating combination adapted for use in treating hair to form a permanent wave therein comprising a reactive metal selected from the metals positioned below the alkali and alkaline earth metals in the electromotive series of metals, a non-deliquescent alkaline hydroxide which in the mixture is' stable within practical limits under normal conditions of storage and of handling in the process of waving hair involving considerable exposure in open air, and a second electrolyte which in aqueous solution will interact with said alkaline hydroxide to produce a non-volatile alkali which will attack said reactive metal with the generation of heat.

6. A chemical heating composition comprising a reactive metal selected from the group consisting of magnesium, aluminum, manganese, and zinc, a non-deliquescent hydroxide, and a second electrolyte which in aqueous solution will interact with said hydroxide to produce a non-volatile alkali which will attack said reactive metal with the generation of heat, said second electrolyte being selected from the group consisting of the sulphates, carbonates, chromates and fluorides of thealkali metals.

'7. A chemical heating combination adapted for use in treating hair to form a permanent wave therein comprising a reactive metal selected from the metals positioned below the alkali and alkaline earth metals in the electromotive series of metals, a relatively stable, non-deliquescent hydroxide which, upon addition of a suitable ionizing medium, will produce an alkaline solution which will attack said reactive metal with the evolution of heat, and an oxidizing agent which, if air is partially excluded from the composition, will supply suflicient oxygen to sustain the heat producing reaction.

8. A chemical heating composition adapted for use in treating hair to form a permanent wave therein comprising a reactive metal selected from the metals positioned below the alkali and alkaline earth metals in the electromotive series of metals, a relatively stable, non-deliquescent hydroxide which, upon addition of a suitable ionizing medium, will produce an alkaline solution which will attack said reactive metal with the evolution of heat, and an oxidizing agent selected from the group consisting oi the chlorates, perborates, permanganates and dichromates of the alkali and alkaline earth metals 9. A chemical heating combination for a heat pad to be used in treating hair to form a wave therein comprising a reactive metal selected from the metals positioned below the alkali and alkaline earth metals in the electromotive series of metals, a compound of ammonium and a non-deliquescent hydroxide which, upon addition of an aqueous ionizing medium, will produce an alkaline solution which will act both to attack the said reactive metal with the generation of heat and to swell the hair to aid in formation of a permanent wave thereinunder the action of the heat generated by the composition.

10. A chemical heating combination adapted for use in treating hair to form a permanent wave therein comprising a reactive metal selected from the metals positioned below the alkali and alkaline earth metals in the electromotive series of metals, an ammonium compound, anda non-deliquescent alkaline hydroxide.

RAYMOND E. REID. 

